The Zimbabwean Gardener Issue 19 Summer 2016/17 | Page 17

hydrangeas
on size – be bold! Hydrangeas need
plenty of rich compost to reach their
potential.
Soil preparation
Soil preparation is very important! The
reward you reap in terms of healthy
growth and flower yield will be
proportional to the care and effort you
put into preparing the planting holes or
containers. If you are planting directly
into the garden, be sure to dig generous
holes that measure at least 60 x 60 x
60cm and fill them with a mixture of
topsoil, good quality compost and about
100g of fertiliser with a high phosphate
content.
Drench with at least two buckets of
water to settle the soil mix. You will
probably find that once the soil mix
has settled, you may need to add more
soil. Then plant the hydrangea a day or
two later without disturbing the roots.
After planting, drench again and apply a
generous amount of mulch to cover all
bare soil.
Hydrangeas at Picabella Nursery(above and below right) and dried hydrangeas (below left)
Water
Hydrangeas love water! They produce
a mass of large leaves that lose a lot of
water through transpiration. Therefore,
their water requirement is high. As a
guide, a large plant in the garden may
need up to 30 to 35l of water per week,
but this will vary according to plant size
and temperature. Mulching is a must
and will prevent water loss from the soil
surface. It also keeps the roots cool and
the weeds out! Hydrangeas are not water
wise, so if you do have a shortage of
water, grow them in well-mulched pots.
Feeding
The plants are also gross feeders and in
order to support the mass of vegetative
growth and abundant flowers they
produce, we suggest about 30g of
fertiliser that has moderate nitrogen,
low phosphate and high potash, per
plant per month, starting in early spring
and continuing until the flowers have
matured.
Pest and disease protection
The most common disease that is
likely to occur is powdery mildew.
Regular spraying with any broad-
spectrum fungicide, such as Kobe or
Chlorothalonil, every two weeks should
afford adequate protection. If you mix
Gil Laver caring for his hydrangeas at Picabella Nursery.
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